Physico-chemical and foaming properties of nanofibrillated egg white protein and its functionality in meringue batter

In the current study, the foaming properties of native egg white proteins (EWP) were compared to those of fibrillated EWP formed by the heating of EWP solution at acidic condition. Transmission electron microscopy (TEM) revealed that different fibrillated morphologies were formed dependent on heating duration. In general, foams produced from fibrillated EWP, particularly the fibrillated EWP prepared from incubation time of 48 h, showed greater stability when compared with those from native EWP at a pH range of 3–9. As a proof-of-concept for the functionality of these fibrillated EWP in a real food system, overrun and rheological properties of meringue batters produced using the fibrillated EWP compared to those made by native EWP. While meringue batters prepared from native EWP showed a runny consistency and could not maintain their shape after shaping, meringue batters made by fibrillated EWP have more solid consistency and overrun and were able to maintain their shape. The rheological data showed batters prepared from fibrillated EWP had higher zero-shear viscosity, yield stress, elastic module, and greater shear thinning behaviour over those made from native EWP, attributing to the presence of fibril chain entanglements in former batters. This study suggested that fibrillated EWP could be used as versatile thickening and texturizing agents in aerated confectionery products that will offer food manufacturers greater control over the texture and consistency of formulated foods.